title: Risk of pneumonia and pneumococcal disease in people hospitalized with diabetes mellitus: English record-linkage studies.
abstract: BACKGROUND
  The risk of invasive pneumococcal disease is higher in people with diabetes mellitus than those without. People with diabetes should be considered for routine pneumococcal immunization. This policy has been in place in England for more than a decade. We aimed to estimate, at the population level, the current scale of excess risk of pneumococcal disease in patients with diabetes, and whether the risks have decreased in recent years with the introduction of a pneumococcal vaccine.
  
  
  METHODS
  We used two data sets of linked hospital admission and death records-the Oxford Record Linkage Study (1963-1998) and all-England linked hospital episode statistics (1999-2011). As a measure of relative risk, we calculated the rate ratio of pneumococcal disease in cohorts of people hospitalized with diabetes compared with cohorts without a record of diabetes.
  
  
  RESULTS
  The risk of pneumococcal disease in patients hospitalized with diabetes mellitus has declined a little, but it is still high. The all-ages rate ratio in England declined from 1.92 (95% CI 1.89-1.94) in 1999-2002 to 1.68 (95% CI 1.65-1.71) in 2007-2011. In people aged under 60 years, rate ratios were higher and their decline was more substantial: rate ratios declined from 3.37 (95% CI 3.28-3.46) in 1999-2002 to 2.33 (95% CI 2.21-2.45) in 2007-2011.
  
  
  CONCLUSIONS
  Patients admitted to hospital with diabetes mellitus remain at increased risk of pneumococcal infection despite a national immunization policy. Possible explanations for the elevated risk include low vaccine uptake or low effectiveness of available vaccine. Clinicians should be aware of the risk of pneumococcal infection in people with diabetes.
authors.affiliation: Unit of Health-Care Epidemiology, Department of Public Health, University of Oxford, Oxford, UK.
authors.forename: O O
authors.initials: OO
authors.lastname: Seminog
authors.forename: M J
authors.initials: MJ
authors.lastname: Goldacre
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000453:epidemiology / Q000276:immunology*; D004739:England / Q000453:epidemiology; D005260:Female; D006291:Health Policy; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008498:Medical Record Linkage; D008875:Middle Aged; D010342:Patient Acceptance of Health Care; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000209:etiology; D022242:Pneumococcal Vaccines / Q000008:administration & dosage; D011014:Pneumonia / Q000453:epidemiology* / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D014611:Vaccination / Q000706:statistics & numerical data*
chemical_list: D022242:Pneumococcal Vaccines